Blasting-cap protector



July 24, 192s.

G. A. LIVERMORE BLASTING CAP PROTECTOR Filed Jan. l19, 1927 Patented July 24, i928.`

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GEORGE AA. LIVERMORE, .OE Jornrmjiarssounr, AssIeNoE 'ro Y COMPANY, OE NEW YORK, N.;Y.,

Af oOEroRa'rioN OE'NEw YORKi y maisTine-oarzPROTECTOR.A

applicati@ ined January 19, iea'i. serial No; 162,172'. A

Thisinvention relates to the protection of detonating fuse elements used 1n blasting,

'.suoh an element comprising a fuse with a detonating cap at the end thereof.

My object is to provide an effective means for protecting said against deterioration and accidental lpercussion, and more particularly against thev I effects of abrasion when placing thereXplosive charge containingy the detonator in a blasting hole, or withdrawing the detonator tector in place upon the detonating element.

n ating from an unexploded charge. 1 U

Of the accompanying drawings, Fig. 1

is a longitudinal section of a protector vconstructed according to my invention. f

Fig. 2 is a similar view showing the pro- Fig. 3 is a longitudinal section showing a blasting charge Aassembled with a detothereto. y

In the drawings, 10 represents acommon form of blasting fuse with a water-proofed exterior and a detonating cap 11 on the end thereof, said cap comprising a metallic shell or cartridge containing a fulminate and having its mouth end crimped ,upon the .fuse at 12.

13 is the protector made of vulcanized, soft-rubber composition. and Vformed kas a deep cup-shaped member adapted to be slipped over the fuse element and completely to enclose the exposed portion thereof, to-

y gether with a part of the fuse 10 adjacent to theA cap 1l. i 9

"The protector 13 is formed with a 'chamber or aperture, of which the portion-.14: forabout one-half the length of said aperture at the closed end is cylindrical and pro# vided with walls of suitable thickness to act as a cushion and to transmit the endwise thrust in applying the protector, whileI said aperture in its remaining portion 15 tapers Aslightly to a restricted diameter at the mouth end. The walls surrounding the tapered portion also taper to la reduced thickness toward the mouth end and at the mouth there is form-ed a circumferential reinforcing bead 16 which tends to keep the mouth edge from buckling or turning in as the protector is forced into place.

The cylindrical portion 14 of the aperture is made slightly larger and the tapered portion 15 at the mouth Iis made'slightly smaller .than the Vdiameter of the fuse and detonating element end. 'to remove the protector when once applied,

fuse havingmyV protector applied cap so that the mouth will Vhave rto be ITHE B. E. Goonnron j stretched tol get iton and when .the protector is in place it will grip the fuse and. resist being pulled off. A`The ldevice may readily 'be applied by wetting the metal shell of.l the detonatling cap to furnish lubrication while the protector 13 ris being slipped l thereover by pushing with endwisepress ure of the fingers until Ait vreaches the posi# tion substantially as shown in Fig. 2p The resistance to removal is very pronounced,

as the constrictive forceincreases with any drawing out andv consequenty contraction of the mouth by a pull exerted atzthe closed If' for any reason it should be desired this may readily be done by rolling lit back forV about half its length from the mouth end and then slipping it off.

Fig. 3 illustrates the manner in which the detonator is commonly appliedto a'blast-y ing charge, 17 representing a'stick of'dynamite in which, with a 4suitable probe are formed two holes slanting in Opposite directions at successive longitudinal positions.

A fuse 10 with the rubber protector v13y covering vthe detonating cap thereof is forced through thel upper hole from one side to the other and then into the lower yhole as shown. While rthe fuse is sometimes placedfaxially |in one end of the charge,

the method illustrated is better adapted to a stamping .bar for ramming the ehargevinto theblasting hole. On the other hand, this zigzag Stringing of the fuse 1s" more apt to expose the end of thecap and render it` subl permit accessto the end of the stick 17 with' ject to abrasion and percussion by roughf ness on the sidesv of the blasting hole, a cause which sometimes produces `premature eX- plosion with resulting injury ory loss. of life.

It alsoA occasionally happensthat a live fuse me .l i

ing the joint between the metal shell of the v cap 11 and the fuse 10 it avoids or delaysl the entrance. of meie'ture Minto the :fulminetv-e` or into the powderf'n the fuse, Vnd :thus

4 tends to prevent deterioration.

. `A pretector fer lllplasng: fuseScomprsl* Vtrhe aperfgure'also tapering ,toi reduced 10 thickness ltuward .fthefmouth end.

,Q c .2.A1-proteetor according to claim 1, having a crcumferenial, reinforcing vbead at lts meut-h.

vIn Witness whereof I yhave lhereunto set!" 1,5 Vmyhandthis 12th day `of January, 1927.

,GEORGE A. LIVERMORE 

